The implications of trace metal-nitrilotriacetetic acid speciation on its environmental impact and toxicology

Substitution of nitrilotriacetic acid (NTA) for polyphosphates in detergents has brought questions concerning its potential toxicity and impact on trace metal distribution in the environment. A calculation based upon metal ligand equilibria, known environmental concentrations of NTA following extensive detergent usage, and the presence of competitive metal-binding ligands and trace elements demonstrates that NTA will be present almost completely as the calcium and magnesium chelates. An analogous estimate of the speciation of NTA in various toxicity studies demonstrates that the onset of chronic toxicity in feeding studies is coincident with the presence of significant concentrations of "free" NTA in the gastrointestinal tract. Massive doses of NTA over long periods of time cause reproducible renal tumors in rats, but dosages of 7500 ppm administered indefinitely are without measurable effect.

Regional enteritis with major gastrointestinal hemorrhage as the initial manifestation

Four patients with massive gastrointestinal hemorrhage were found to have Crohn's ileitis. This prompted a five-year chart review of consecutive admissions for Crohn's enteritis; 60 patients were found whose disease was limited to the distal part of the ileum (and rarely the proximal part of the cecum). Eight (13%) of these patients were admitted because of major rectal bleeding, and in seven of the eight the hemorrhage was the initial manifestation of Crohn's disease. The mean age of the entire group was 30 years, with a mean age of 18.6 years in the eight bleeders. Crohn's ileitis should be considered in the differential diagnosis of massive rectal bleeding, especially in younger patients.

The conservative management of anorectal cancer by radiotherapy

Thirteen patients with an anal or rectal carcinoma were given curative radiotherapy. Four had medically inoperable tumors, one had a surgically inoperable tumor and eight refused abdominoperineal resection. Six patients received external radiotherapy only. Seven patients received external radiotherapy and an interstitial implant. Nine of thirteen patients (60 per cent) are alive without evidence of disease from fifteen to fifty-five months (average, 30 months). Six of seven patients who received external radiotherapy combined with an interstitial implant were controlled locally, whereas three of six patients who received external radiotherapy only were controlled. Patients who underwent total excision and/or fulguration prior to irradiation had better local control than those who underwent either biopsy only or a subtotal excision. This treatment method may be offered as an alternative to abdominoperineal resection in patients who are medically unfit or who refuse surgery.

The clinical significance of bundle branch block complicating acute myocardial infarction. 1. Clinical characteristics, hospital mortality, and one-year follow-up

To provide an understanding of the clinical characteristics of patients with acute myocardial infarction (MI) and bundle branch block, experience from five centers was accumulated. Patients in whom bundle branch block first appeared after the onset of cardiogenic shock were excluded. In 432 patients, the most common types of block were left (38%) and right with left anterior fascicular block (34%). In 42% of the patients, bundle branch block was new. Progression to high degree (second or third degree) atrioventricular (AV) block via a Type II pattern occurred in 22% of the patients. Hospital and first year follow-up mortality rates were 28% and 28%, respectively. Only 46% of the patients developed pulmonary edema or shock (Killip Class III or IV), and hospital mortality was related to the amount of heart failure (8%, 7%, 27%, 83% for Killip Classes I-IV, respectively). Patients with progression to second degree or third degree AV block via a Type II pattern had increased hospital mortality compared with patients without this complication (47% vs 23%, P less than 0.001). In the absence of pulmonary edema or shock, patients with Type II second degree or third degree AV block still had a higher mortality rate than patients without advanced AV block (31% vs 2%, P less than 0.005), with nearly all the deaths due to abrupt development of AV block. Thus, in many patients MI with bundle branch block is associated with severe heart failure. However, this was not true for a majority of the patients, in whom therapy aimed at preventing morbidity and mortality due to the bradyarrhythmia of advanced AV block might be beneficial.

The clinical significance of bundle branch block complicating acute myocardial infarction. 2. Indications for temporary and permanent pacemaker insertion

The indication for prophylactic temporary and permanent pacing during acute myocardial infarction (MI) complicated by bundle branch block is high risk of progression via a Type II pattern to second or third degree (high degree) AV block during hospitalization or follow-up. In this study, determinants of high degree AV block during hospitalization and sudden death or recurrent high degree block during the first year of follow-up were examined in 432 patients with MI and bundle branch block. Timing of onset of bundle branch block, the involved fascicles, and the PR interval were examined as determinants of risk of progression to high degree AV block during MI. At highest risk were 186 patients with blocks involving the right bundle and at least one fascicle of the left bundle which were not documented on prior electrocardiograms. Risk was similar with (38%) or without (31%) accompanying first degree AV block. Patients with transient high degree AV block during MI had a 28% incidence of sudden death or recurrent high degree block during the first year of follow-up. Patients not continuously paced had a higher incidence of sudden death or recurrent high degree block than patients continuously paced (65% vs 10%, P less than 0.001). Sudden death during follow-up also occurred in 13% of patients without high degree block during MI. A subgroup with 1) documented prior MI, 2) anterior or indeterminant acute MI, and 3) no symptoms of cardiac failure had a 35% risk of sudden death. The role of permanent pacing in this group is unknown. Thus, patients at high risk of high degree AV block should receive prophylactic temporary pacing. Patients who survive high degree block with MI should receive temporary and then permanent pacing. Patients without high degree AV block during MI who nervertheless have a high risk of sudden death may benefit from permanent pacing.

Dissolution of Barium-impaction ileus by Gastrografin

Ileus caused by impaction of hardened residual barium stagnated in the colon-a rare complication of barium-meal examination-constitutes a particularly serious problem when it occurs following abdominal operations, leading to postoperative ileus. The administration of Gastrografin in such cases has proven efficacy in the dissolution of inspissated barium, refractory to routine means of evacuation. Four case reports provide an illustration of this problem. The satisfactory results obtained, and the hitherto reported lack of side effects of this compound, justify recommendation of Gastrografin as a safe, simple method for use in the management of these cases.

Analysis of terminal structures of RNA from potato virus X

The 5'-end structure of potato virus X RNA was determined following enzymatic methylation in vitro. A single 3H-methyl group was introduced into the 2'-position of the 5'-penultimate residue and the end structure was determined as m7GpppG(m)pAp(Xp)3G. This part of the RNA apparently is involved in binding to ribosomes since it can be partially protected against RNase digestion by wheat germ 40S ribosomes. PVX RNA was not retained by poly(U)-sepharose, indicating that it does not contain a 3'-terminal poly(A) tract.

S-100 protein in guinea pig brain during prenatal development

Nervous tissue-specific S-100 protein was quantified immunologically in maturing cerebrum, cerebellum and brain stem of guinea pigs during prenatal development. It was found to accumulate in its membrane-bound (pentanol-extractable) form concomitant with the accumulation of the water-soluble S-100 during development, indicating an ability of membranous structures to incorporate S-100 already during development.

A new abrasive applicator for human enamel biopsy procedures

Experiments were performed that demonstrated that the felt cylinder usually used to obtain abrasive biopsy specimens did not uniformly remove enamel from rounded or irregular enamel surfaces in the window area. A foam-silicone rubber laminate was developed to replace the felt cylinder. This resulted in greater uniformity of abrasion over the enamel surface within the biopsy window area and better operator handling characteristics.

Psychological factors and clinical observations in acupuncture analgesia and pain abatement

The present study attempted to (a) replicate findings on acupuncture reported in the Chinese literature; (b) investigate the effects of acupuncture in achieving analgesia and pain abatement; and (c) isolate the relevant psychological and/or physiological variables involved. Fifty volunteer men and women between 18 and 30 years of age were administered the acupuncture phase of this study for induction of analgesia and relief of pain in the oral cavity. A comparable group of 30 additional Ss were included in the study for comparison with the acupuncture group on several objective psychological measures. Forty of the acupuncture Ss were classified as totally successful. No significant differences between the acupuncture group and the comparable control group were obtained on the objective psychological measures, including measures of personality, suggestibility, anxiety, and attitudes. The results appear to indicate that psychological factors are minimally involved in obtaining analgesia and pain abatement with acupuncture techniques. Several interesting clinical observations were noted during the acupuncture procedure, including absence of discernable signs of analgesia, consistency of results, contralateral analgesic effect related to the location of acupuncture needles, etc. These results were discussed in terms of the possible role of physiological and psychological factors in acupuncture. Possible areas of future research were also discussed.

Petroleum Pollutants in Surface and Groundwater as Indicated by the Carbon-14 Activity of Dissolved Organic Carbon

The (14)C activity of dissolved organic carbon (DOC) can be used to distinguish between the fossil organic carbon due to petrochemical effluents and modern organic carbon due to domestic wastes and natural decaying organic matter. Rivers polluted by petrochemical effluents show varying amounts of depression of the DOC (14)C activity, reflecting concentrations of (14)C-deficient fossil carbon of as much as about 40 percent of the total DOC.

[A trial of the treatment of the premenstrual syndrome by acupuncture]

After a clinical and physiopathological review of the premenstrual syndrome, the author reports six cases of patients showing these symptoms who were treated exclusively by acupuncture. The clear improvement shown makes it worthwhile to continue the trial and to extend it to include other domains of functional gynaecology.

Methane in Lake Kivu: New Data Bearing on Its Origin

Lake Kivu, an African rift lake, contains about 50 cubic kilometers of methane (at standard temperature and pressure) in its deep water. Data resulting from two recent expeditions to the lake and a reevaluation of earlier data suggest that most of the methane was formed by bacteria from abiogenetic carbon dioxide and hydrogen, rather than being of volcanic origin or having formed from decomposing organic matter.

Freshwater Peat on the Continental Shelf

Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.